Q: If you write a GUI app for Windows and Linux, is the same code used for both?

A: Yes. A single Xojo desktop project can be built for Windows, Linux and Mac OS using the exact same UI layout and source code. Of course, you can also provide OS-specific source code when necessary as well by using Conditional Compilation.

Q: How do you handle the layout and positioning of controls when the form is resized?

A: With a Xojo desktop app you can use the “locking” feature to lock controls to edges of the window. You can also use the Resized/Resizing event handlers on the Window class to position controls more precisely as the window is resized.

With iOS, you use Auto-Layout to position controls related to the view size and to other controls on the view.